Welding strain prevention device

Abstract

To provide a welding strain prevention device which can improve operability and can reduce an operation time, in the welding strain prevention device which prevents the occurrence of welding strain by cooling a member by the use of liquid.SOLUTION: A welding strain prevention device that is the welding strain prevention device for cooling a heat-affected portion of the member upon welding by using liquid includes: a box body having an opening part which stores the liquid in an internal space and opens the internal space, and a transparent window through which surface height of the liquid can be visualized; an evacuation port communicated with the internal space and connected to a vacuum device; a liquid supply port communicated with the internal space and supplying the liquid to the internal space therethrough; and a packing provided on a peripheral part of the opening part or on a position on the outer circumferential side of the peripheral part.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a welding distortion prevention device that cools a heat-affected zone during welding to prevent welding distortion occurring in members. [Background technology]

[0002] Patent Document 1 discloses a jig for preventing butt welding deformation in plate material that uses a simple cooling means to block the conduction of welding heat that is guided along the plate material from the butt welded portion of the plate material, thereby preventing the occurrence of residual deformation in the plate material. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2001-071129 A Summary of the Invention [Problem to be solved by the invention]

[0004] In Patent Document 1, bottom-open shells 7, 7 are temporarily installed by adhesive 10 or tack welding so that the lower periphery is fluid-tightly attached to the plate material 4 in advance along the vicinity of the butt welded portion 1. Patent Document 1 discloses an embodiment in which a cooling line is formed along both sides of the plate material welded portion 1 because a coolant is circulated inside the shells 7, 7. Alternatively, Patent Document 1 discloses an embodiment in which bottom-open shells 7 are previously arranged in pairs on the left and right along the vicinity of the plate material edge to be welded, and a packing 11 is provided between the lower periphery of each shell 7 and the surface of the plate material 4. In both of these, the bottom-open shells are fluid-tightly attached to the plate material 4, but in the former, the lower periphery of each shell 7 must be temporarily installed by adhesive 10 or tack welding as a shell attachment means. In the latter, a pressing means such as a weight must be installed on the shell as a means for attaching the packing 11 to the surface of the plate material 4. Therefore, in the former case, preparatory work such as applying adhesive or temporary welding is required, and post-processing such as removing the adhesive or removing the temporary welding bead is required, while in the latter case, work such as installing and removing a weight is required, which leads to loss of work time.

[0005] Therefore, the present disclosure aims to provide a welding distortion prevention device that prevents the occurrence of welding distortion in components due to the thermal effects during welding by cooling the components with liquid, which can improve workability and shorten work time. [Means for solving the problem]

[0006] A welding distortion prevention device according to one embodiment of the present disclosure is a welding distortion prevention device that uses liquid to cool the heat-affected zone of a component during welding, and includes a box body that stores the liquid in an internal space, an opening that opens the internal space, and a transparent window through which the liquid level of the liquid can be visually observed, a vacuum port that communicates with the internal space and is connected to a vacuum device, a liquid supply port that communicates with the internal space and supplies the liquid to the internal space, and a gasket provided on the periphery of the opening or on the outer circumferential side of the periphery. Effect of the Invention

[0007] According to the welding distortion prevention device having the above configuration, the box body is fixed to the member via the packing by creating a negative pressure in the internal space with a vacuum device. If liquid is supplied from the liquid supply port and stored in the internal space, the liquid can be used to cool the heat-affected parts of the members during welding, making it possible to cool them with simple work by the worker. This reduces the amount of work required by the worker when cooling the members that are affected by heat during welding. [Brief description of the drawings]

[0008] [Figure 1] FIG. 2 is a perspective view of a welding distortion prevention device according to an embodiment. [Diagram 2] FIG. 2 is a cross-sectional view of the welding distortion prevention device of FIG. 1 during cooling. [Diagram 3] FIG. 2 is a perspective view of the welding distortion prevention device of FIG. 1 during cooling. [Figure 4] FIG. 11 is a perspective view of a welding distortion prevention device according to another embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, a welding distortion prevention device according to an embodiment will be described with reference to the accompanying drawings. Fig. 1 shows a perspective view of a welding distortion prevention device 1 according to an embodiment. Fig. 2 shows a cross-sectional view of the welding distortion prevention device 1 according to an embodiment, taken along a plane extending in the up-down and front-rear directions at approximately the center position in the width direction D1. Hereinafter, the width direction of the welding distortion prevention device 1 will be referred to as D1, the direction perpendicular to the width direction D1 in the horizontal plane as the front-rear direction D2, and the up-down direction as D3.

[0010] The welding distortion prevention device 1 is a device for preventing the occurrence of welding distortion by cooling the heat-affected zone S of the workpiece caused by the heat during welding. The welding distortion prevention device 1 includes a box body 2. The box body 2 is placed on the workpiece W so as to cover the heat-affected zone S of the workpiece W from above in order to cool the heat-affected zone S caused by the heat when welding the welded portion P. In this embodiment, the workpiece W is composed of a roof panel W1 of a railway vehicle, a rafter W2, and an adapter W3. The adapter W3 is connected to the rafter W2 by welding. By connecting the adapter W3 to the rafter W2, an interior item can be attached to the roof panel W1 via the adapter W3. The heat-affected zone S refers to a portion where welding heat generated at the welded portion P between the adapter W3 and the rafter W2 propagates onto the roof panel W1 when the adapter W3 is connected to the rafter W2 by welding, and distortion may occur in the roof panel W1 due to the welding heat. During cooling, the heat-affected zone S of the roof plate W1 of the workpiece W is surrounded by the box body 2. Here, the heat-affected zone S refers to the portion of the roof plate W1 that is covered by the box body 2 and where distortion may occur due to welding heat.

[0011] In this embodiment, the box body 2 is manufactured from resin using a 3D printer. Since the box body 2 is manufactured using a 3D printer, the box body 2 can be manufactured in the shape of each part of the welded portion to be cooled, and a seamless box body 2 can be realized. This makes it possible to easily manufacture the box body 2 in the shape of each part to be cooled. The manufacturing method of the box body 2 can be realized without using a 3D printer.

[0012] The box body 2 is configured to define an internal space 3 on the inside. The box body 2 has an opening 4 that opens the internal space 3 to the outside. The box body 2 has a box body main body portion 2a and is configured to be concave from the opening 4 inward. The opening 4 is defined by a peripheral portion 5 of the box body 2. A packing 6 is provided on the peripheral portion 5 of the box body 2. The packing 6 is attached to the box body 2 so as to seal between the box body 2 and the workpiece W. This makes it possible to prevent the liquid stored in the internal space 3 from leaking to the outside from the opening 4 of the box body 2. The packing 6 is formed of a flexible material to seal between the box body 2 and the workpiece W. In this embodiment, for example, the packing 6 is formed of a sponge tape having a tape surface for adhesion formed on a sponge body. In this embodiment, the packing 6 is configured to be provided on the peripheral portion 5 of the opening 4 in the box body 2, but the packing 6 may be located on the outer periphery side of the peripheral portion 5 of the opening 4. In other words, the packing 6 needs to be disposed at a position where it can prevent liquid from leaking from the internal space 3.

[0013] In this embodiment, the welding distortion prevention device 1 has a first transparent window 18 for checking the level of the liquid stored in the internal space 3, which is separate from the box body main body 2a, and a second transparent window 19 for checking the state of the internal space 3, which is separate from the box body main body 2a. The box body 2a has a first hole 2b that opens the internal space 3 and a first peripheral portion 2c that defines the first hole 2b. The first transparent window 18 is fitted from the outside into a step portion provided around the first peripheral portion 2c, and is sealed all around. As a result, the first transparent window 18 is attached to the box body 2a so as to close the first hole 2b. The first transparent window 18 is made of a transparent material so that the level of the liquid stored in the internal space 3 can be visually checked from the outside. The first transparent window 18 is formed on a side surface 2f of the box body main body 2a, and is formed over substantially the entire box body main body 2a in the up-down direction D3.

[0014] The box body 2a also has a second hole 2d that opens the internal space 3 and a second peripheral portion 2e that defines the second hole 2d. The second transparent window 19 is fitted from the outside by a step portion provided around the second peripheral portion 2e, and is sealed all around. As a result, the second transparent window 19 is attached to the box body 2a so as to close the second hole 2d. The second transparent window 19 is made of a transparent material so that the desired position of the work W and the liquid level can be visually confirmed from the outside. The second transparent window 19 is formed on the upper surface 2g of the box body 2a. In this embodiment, the second transparent window 19 has a larger area than the first transparent window 18. Note that the first transparent window 18 may be marked with a scale so that the height of the liquid level can be accurately confirmed. In this embodiment, the first transparent window 18 and the second transparent window 19 are formed in a plate shape. In this embodiment, for example, the first transparent window 18 and the second transparent window 19 are made of a plate-shaped transparent resin, such as polycarbonate.

[0015] The box 2 has a protruding portion 8 that protrudes in one direction in the front-rear direction D2 beyond a portion where the second transparent window 19 is provided. The protruding portion 8 protrudes in one direction in the front-rear direction D2 only in a part of the width direction D1. The protruding portion 8 is configured to define an inner protruding portion internal space 3b. The protruding portion internal space 3b is configured as a part of the internal space 3. In other words, the internal space 3 has a main space 3a and a protruding portion internal space 3b.

[0016] The welding distortion prevention device 1 includes a vacuum port 10. The vacuum port 10 is connected to the protruding inner space 3b and is connected to a vacuum device such as a vacuum pump. The vacuum port 10 is connected to the vacuum device via an air supply pipe 11 that allows air to flow. By operating the vacuum device, air can be forcibly discharged from the internal space 3, thereby making the internal space 3 a vacuum. In addition, the device is configured to be able to adjust the pressure inside the internal space 3 by adjusting the amount of air discharged from the vacuum device. In this embodiment, a vacuum ejector is used as the vacuum device.

[0017] In this embodiment, the vacuum port 10 is provided at the top of the protruding portion 8 of the box body 2, and is arranged on the vertically upward side of the box body 2. Particularly in this embodiment, the vacuum port 10 is provided in the box body 2 so as to communicate with the highest position of the internal space 3.

[0018] The welding distortion prevention device 1 has a liquid supply port 12 that communicates with the internal space 3. The liquid supply port 12 is connected to a liquid supply pipe 13 that can circulate liquid inside. The liquid supply pipe 13 is connected to, for example, a tank in which liquid is stored. In addition, the liquid supply pipe 13 is provided with a flow rate control valve 14 that can adjust the flow rate of the liquid inside the liquid supply pipe 13. In this embodiment, water is used as the liquid stored in the internal space 3.

[0019] The welding distortion prevention device 1 has a liquid drainage port 15 arranged at a lower position in the box body 2. The liquid drainage port 15 is connected to the internal space 3 and is configured to be able to discharge the liquid stored in the internal space 3 to the outside. The liquid drainage port 15 is connected to a liquid drain pipe 16 that can circulate the liquid. In addition, the liquid drain pipe 16 is connected to a negative pressure forming device that forms a negative pressure, and the liquid stored in the internal space 3 can be discharged to the outside or returned to a storage tank by using the differential pressure with the internal space 3. The negative pressure forming device of this embodiment employs a vacuum ejector, similar to the vacuum drawing device. The operating procedures of these will be described later.

[0020] The box body 2a of the box body 2 has a protrusion 17 protruding from the inner periphery 5a of the peripheral portion 5 of the opening 4 of the box body 2 in the direction in which the packing 6 is pressed against the workpiece W. Since the protrusion 17 is provided from the inner periphery 5a of the peripheral portion 5 toward the workpiece W, the protrusion 17 is located on the inside of the packing 6 in the horizontal direction. In other words, the protrusion 17 is provided on the inside of the packing 6 in the width direction D1 and the front-rear direction D2 at the peripheral portion 5 of the box body 2. Since the protrusion 17 is arranged on the inside of the packing 6, when the packing 6 is drawn into the internal space 3 during evacuation, the protrusion 17 abuts against the packing 6 to prevent the packing 6 from moving inward. Therefore, it is possible to prevent a gap from being generated between the peripheral portion 5 of the box body 2 and the workpiece W, the vacuum inside the internal space 3 is maintained, and the stability of the welding distortion prevention device 1 in use is increased.

[0021] The welding distortion prevention device 1 configured as described above is used to cool the heat-affected zone S of the workpiece W that propagates to the roof plate W1 when welding the welded portion P. FIG. 3 shows a perspective view of the state in which the welding distortion prevention device 1 is used to cool the heat-affected zone S. When cooling is performed, the welding distortion prevention device 1 is placed on the roof plate W1 of the workpiece W so that the packing 6 surrounds the heat-affected zone S of the workpiece W. Then, the internal space 3 is evacuated through the vacuum port 10. At that time, air is discharged from the internal space 3 through the vacuum port 10 in the direction shown by the arrow D4 in FIG. 3. Then, when it is confirmed that the inside of the internal space 3 is evacuated and the packing 6 is in close contact with the roof plate W1 of the workpiece W, the flow rate control valve 14 is opened. Then, liquid is supplied to the internal space 3 through the liquid supply port 12 due to the pressure difference with the atmospheric pressure. At that time, liquid is supplied toward the internal space 3 in the direction shown by the arrow D6 in FIG. 3. This allows liquid to be stored in the internal space 3 of the box body 2.

[0022] Since the box 2 has the first transparent window 18 and the second transparent window 19, when storing liquid in the internal space 3 through the liquid supply port 12, the operator supplies the liquid while checking the position of the liquid surface inside the internal space 3. This allows the operator to store an appropriate amount of liquid in the internal space 3.

[0023] The box 2 is placed on the roof panel W1 including the heat-affected zone S, and liquid is stored inside the internal space 3, so that the heat of the heat-affected zone S is transferred to the liquid. Therefore, the heat of the heat-affected zone S is taken away by the liquid, and the temperature of the heat-affected zone S drops. This makes it possible to prevent welding distortion from occurring in the roof panel W1 including the heat-affected zone S.

[0024] When the heat-affected zone S is cooled by the welded portion P and the liquid stored in the internal space 3 becomes hot, the liquid in the internal space 3 can be discharged by operating the negative pressure forming device communicating with the liquid drainage port 15. The procedure is to operate the negative pressure forming device communicating with the liquid drainage port 15 while maintaining the vacuum state of the internal space 3, and adjust the pressure of both ports so that the pressure of the liquid drainage port 15 is lower than the pressure of the vacuum drawing port 10. When a considerable amount of liquid in the internal space 3 is discharged, the liquid in the internal space 3 can be replaced by supplying liquid again from the liquid supply port 12 to the internal space 3. At that time, the liquid is discharged from the internal space 3 through the liquid drainage port 15 in the direction shown by the arrow D5 in FIG. 3, and the liquid is supplied to the internal space 3 through the liquid supply port 12 in the direction shown by the arrow D6 in FIG. 3. As a result, low-temperature liquid that has not undergone heat exchange is supplied to the inside of the internal space 3, and the low-temperature liquid effectively cools the heat-affected zone S.

[0025] In this embodiment, the box 2 has a second transparent window 19, and the second transparent window 19 has a larger area than the first transparent window 18 on the upper surface 2g of the box 2. Therefore, even while the heat-affected zone S is being cooled, the worker can cool the heat-affected zone S while checking the state of the heat-affected zone S surrounded by the box 2 from above the box 2.

[0026] According to the above embodiment, the internal space 3 of the box body 2 is evacuated to a vacuum, so that the internal space 3 is under negative pressure. Then, the box body 2 and the workpiece W are in close contact with each other so that the packing 6 is pressed against the workpiece W. When it is confirmed that the box body 2 is fixed to the workpiece W by the negative pressure inside the internal space 3, liquid is introduced into the internal space 3 and the liquid is stored in the internal space 3. Since the liquid inside the internal space 3 comes into contact with the heat-affected zone S, the heat-affected zone S is cooled. At this time, the operator can store the liquid in the internal space 3 simply by opening the flow rate control valve 14 of the liquid supply port 12 with the box body 2 fixed to the workpiece W. Therefore, the operator can cool the heat-affected zone S with a simple operation.

[0027] The box body 2 is placed on the roof plate W1 of the workpiece W, and a negative pressure is formed inside the internal space 3, so that the box body 2 is adsorbed and fixed to the roof plate W1 of the workpiece W. After that, the heat-affected zone S can be cooled simply by supplying liquid to the internal space 3 of the box body 2, so the worker does not need to perform extra work to attach the box body 2 to the workpiece W. Specifically, the worker does not need to perform work to attach a cooling water container to the workpiece by bonding with an adhesive or tack welding, etc. In addition, the worker does not need to perform extra work to remove the box body 2 from the roof plate W1 after cooling is completed. Specifically, the worker does not need to perform extra work to remove the container from the workpiece, such as removing the adhesive or scraping off the tack welded portion. Therefore, the worker can reduce the work process and shorten the work time.

[0028] Furthermore, according to this embodiment, since the vacuum port 10 is disposed on the vertically upper side of the box body 2, it is possible to prevent liquid from entering the vacuum port 10. Therefore, it is possible to prevent liquid from interfering with the discharge of air from the vacuum port 10 during evacuation.

[0029] In addition, according to this embodiment, the welding distortion prevention device 1 has a drainage port 15 that drains the liquid from the internal space 3 by the negative pressure formed by the negative pressure forming device, so that the liquid inside the internal space 3 can be drained from the drainage port 15. Then, by supplying liquid to the internal space 3 again from the liquid supply port 12, the liquid in the internal space 3 can be replaced. Therefore, the heat-affected zone S of the workpiece W can be continuously cooled. In addition, the liquid can be prevented from heating to a high temperature, and the cooling function of the liquid can be prevented from decreasing. Furthermore, if the liquid discharged from the drainage port 15 is returned to the storage tank, the cooling work can be performed with just a tank full of liquid, which is economical.

[0030] According to this embodiment, the workpiece W includes a roof plate W1 of a railroad car, and the heat-affected zone S is cooled in a state where the box body 2 is in close contact with the roof plate W1 of the workpiece W. The welding distortion prevention device 1 has a structure in which a packing 6 is provided around the entire periphery 5 of the opening 4 in the box body 2, making it difficult for liquid to leak from the box body 2 onto the roof plate W1. Therefore, when a worker works at a height, such as on the roof of a railroad car, it is possible to prevent the worker's feet from getting wet due to liquid leaking from between the box body 2 and the workpiece W. This allows the worker to perform the work of cooling the heat-affected zone S more safely.

[0031] Furthermore, according to this embodiment, since the box body 2 is manufactured by a 3D printer, the box body 2 can be manufactured as a seamless structure. Therefore, when the box body 2 is set on the workpiece W and liquid is stored in the internal space 3, it is possible to prevent the liquid from leaking out of the box body 2.

[0032] Also, according to this embodiment, since water is used as the liquid stored in the internal space 3, it is possible to inexpensively cool the heat-affected zone S of the workpiece W during welding. Furthermore, if the liquid discharged from the drainage port 15 is returned to the storage tank, the cooling work can be repeated as long as there is a tank full of liquid, so that the heat-affected zone S can be cooled without any problems even if there is no water facility near the work site. In this way, according to this embodiment, the cost of cooling the heat-affected zone S can be kept low.

[0033] In the above embodiment, the work W has a roof plate W1, a rafter W2 supporting the roof plate W1, and an adapter W3 attached to the rafter W2. The roof plate W1 extends almost straight along the width direction D1 and the front-rear direction D2, and accordingly, the peripheral portion 5 of the opening 4 of the box body 2 and the packing 6 extend straight along the width direction D1 and the front-rear direction D2. However, this is not limited to the above embodiment. The roof plate W1 may have an uneven shape, and when the roof plate W1 has an uneven shape, the peripheral portion 5 of the box body 2 may have an uneven shape that matches the uneven shape of the roof plate W1. In other words, the peripheral portion 5 of the opening 4 of the box body 2 may be formed into a shape that follows the shape of the roof plate W1 when the box body 2 is set on the roof plate W1.

[0034] FIG. 4 shows a perspective view of the welding distortion prevention device 1A and the workpiece W when the roof plate W1a of the workpiece W has an uneven shape. As shown in FIG. 4, the roof plate W1a of the workpiece W is a plate material having an uneven shape. In this embodiment, the welding distortion prevention device 1A is configured so that the peripheral portion 5 of the opening 4 in the welding distortion prevention device 1A has an uneven shape in accordance with the uneven shape of the roof plate W1a, and accordingly, the end faces 20 and 21 in the front-rear direction D2 of the box body 2 have a plurality of recesses 22. The recesses 22 are configured to be recessed upward in the vertical direction. In this embodiment, each recess 22 is formed in a tapered shape at both ends in the width direction D1 so as to be upward as it goes inward. In addition, in accordance with the end faces 20 and 21 in the front-rear direction D2 of the box body 2 having the recesses 22, the packing 6A is arranged to be recessed upward along the recesses 22.

[0035] Since the peripheral portion 5 of the box body 2 has an uneven shape that matches the uneven shape of the workpiece W, even if the workpiece W has unevenness, the peripheral portion 5 of the opening 4 of the box body 2 is formed into a shape that follows the shape of the workpiece W. In this embodiment, the peripheral portion 5 of the opening 4 of the box body 2 is formed into a shape that follows the uneven shape of the roof plate W1a of the workpiece W. Therefore, the packing 6A can be tightly attached to the workpiece W without any gaps. Therefore, it is possible to prevent liquid from leaking out from the opening 4. As a result, the liquid is maintained in the internal space 3 of the box body 2 while the box body 2 is fixed to the workpiece W, and the heat-affected zone S can be continuously cooled.

[0036] In this embodiment, if the welding heat from the welded portion P between the rafter W2 and the adapter W3 propagates from the rafter W2 to the roof plate W1, there is a concern that the roof plate W1 may be distorted. Therefore, it is necessary to cool this heat-affected zone S. In this embodiment, the use of the welding distortion prevention device 1A is illustrated as an example when cooling the heat-affected zone S of the roof plate of a railway vehicle. Some roof plates of railway vehicles have an uneven shape. When cooling the heat-affected zone S in such a roof plate W1a having an uneven shape, it is possible to cool the heat-affected zone S while suppressing liquid leakage by making the box body 2 shaped to match the uneven shape of the roof plate W1a. Therefore, the welding distortion prevention device 1A of this embodiment is suitable for cooling the roof plate W1a of a railway vehicle having an uneven shape.

[0037] In the above embodiment, the configuration in which the second transparent window 19 is provided on the upper surface 2g of the box body main body 2a has been described, but the present invention is not limited to the above embodiment. If there is no need to visually check the state of the heat-affected zone S, the second transparent window 19 may not be provided. The entire upper surface 2g of the box body main body 2a may be formed of the same resin as the other parts of the box body main body 2a. Conversely, if the liquid level can be confirmed from the second transparent window 19 on the upper surface of the box body main body 2a, the first transparent window 18 provided on the side of the box 2 may not be provided.

[0038] In the above embodiment, the vacuum port 10 is provided in the box body 2 so as to communicate with the highest position of the internal space 3, and the vacuum port 10 is connected to the highest position of the box body 2. However, the present invention is not limited to the above embodiment. The vacuum port 10 may be provided in the box body 2 so as to communicate with the internal space 3 at a position other than the highest position of the internal space 3. The vacuum port 10 may not be connected to the highest position of the box body 2. When the air in the internal space 3 is discharged to the outside through the vacuum port 10 and the internal space 3 is evacuated, it is sufficient that no liquid flows into the vacuum port 10. Therefore, it is desirable that the vacuum port 10 is provided in the internal space 3 at a position above the space in which the liquid is expected to be stored. In addition, if it is desired to prevent the liquid from flowing into the vacuum port 10, it is desirable that the vacuum port 10 is provided at a position higher than the liquid supply port 12.

[0039] As described above, the above embodiment has been described as an example of the technology disclosed in this application. However, the technology in this disclosure is not limited to this, and can be applied to embodiments in which modifications, replacements, additions, omissions, etc. have been made as appropriate. In addition, it is also possible to combine the components described in the above embodiment to create a new embodiment. For example, a part of the configuration or method in one embodiment may be applied to another embodiment, and a part of the configuration in an embodiment can be separated from other configurations in that embodiment and arbitrarily extracted. In addition, the components described in the attached drawings and detailed description include not only components essential for solving the problem, but also components that are not essential for solving the problem in order to exemplify the technology.

[0040] Each of the following sections is a disclosure of a preferred embodiment.

[0041] [Item 1] A welding distortion prevention device that uses liquid to cool the heat-affected zone of a member during welding, A welding distortion prevention device comprising: a box body that stores the liquid in an internal space, has an opening that opens the internal space and a transparent window through which the liquid level of the liquid can be visually observed, a vacuum port that communicates with the internal space and is connected to a vacuum device, a liquid supply port that communicates with the internal space and supplies the liquid to the internal space, and a gasket provided on the periphery of the opening or on the outer circumferential side of the periphery.

[0042] [Item 2] 2. The welding distortion prevention device according to claim 1, wherein the vacuum port is disposed on the vertical upper side of the box body.

[0043] [Item 3] 3. The welding distortion prevention device according to item 1 or 2, further comprising a drainage port that is in communication with the internal space and that drains the liquid from the internal space, the drainage port being in communication with the internal space and connected to a negative pressure forming device that forms a negative pressure.

[0044] [Item 4] 4. The welding distortion prevention device according to any one of items 1 to 3, wherein the peripheral portion of the opening of the box body is formed into a shape that follows the shape of the member when the box body is set on the member.

[0045] [Item 5] 5. The welding distortion prevention device according to any one of items 1 to 4, wherein an inner periphery of the peripheral edge of the opening of the box body is provided with a protrusion protruding from the opening end face toward the member.

[0046] [Item 6] 6. The weld distortion prevention device according to any one of items 1 to 5, wherein the member is a roof panel of a railway vehicle.

[0047] [Item 7] The welding distortion prevention device according to any one of items 1 to 6, wherein the box body is manufactured by a 3D printer.

[0048] [Item 8] 8. The welding distortion prevention device according to any one of items 1 to 7, wherein the liquid is water. [Explanation of symbols]

[0049] 1. 1A Welding distortion prevention device 2 box body 18 First transparent window 3. Interior space 4 Openings 5 Periphery 5a Inner circumference 6, 6A Packing 10 Vacuum port 12 Fluid supply port 15 Drainage port 22 Recess S Heat-affected zone P Welding W Work (material) W1 Roof shingle

Claims

1. A welding distortion prevention device that uses liquid to cool the heat-affected zone of a member during welding, A welding distortion prevention device comprising: a box body that stores the liquid in an internal space, has an opening that opens the internal space and a transparent window through which the liquid level of the liquid can be visually observed, a vacuum port that communicates with the internal space and is connected to a vacuum device, a liquid supply port that communicates with the internal space and supplies the liquid to the internal space, and a gasket provided on the periphery of the opening or on the outer circumferential side of the periphery.

2. The welding distortion prevention device according to claim 1 , wherein the vacuum port is disposed on a vertically upper side of the box body.

3. 3. The welding distortion prevention device according to claim 1, further comprising a drainage port communicating with the internal space and discharging the liquid from the internal space, the drainage port being connected to a negative pressure forming device communicating with the internal space and forming a negative pressure.

4. 3. The welding distortion prevention device according to claim 1, wherein the peripheral portion of the opening of the box body is formed into a shape that conforms to a shape of the member when the box body is set on the member.

5. The welding distortion prevention device according to claim 1 , wherein an inner periphery of the peripheral edge of the opening of the box is provided with a protrusion protruding from the opening end face toward the member.

6. 3. The welding distortion prevention device according to claim 1, wherein the member is a roof panel of a railway vehicle.

7. The welding distortion prevention device according to claim 1 or 2, wherein the box body is manufactured by a 3D printer.

8. The welding distortion prevention device according to claim 1 or 2, wherein the liquid is water.

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